Ceramic heaters provides low emissivity as they operate at a hotter surface temperature due to their size. Sunlighten's Solocarbon heaters are much larger and operate at a lower surface temperature. Thus, Solocarbon emits a greater amount of infrared.

What about a blend of Carbon and Ceramic?

Both materials are emissive. Yet, our test data has shown that a blend of carbon and ceramic actually decreases emissivity. View study here.